Keinhaed mannesman



(Model.)

B. MANNESMANN. MANUFACTURE OF SEAMLESS TUBES.

Patented-Apr. 26, 1887.

' UNITED. STATES PATENT OFFICE.

REI'NHARD MANNESMANN, OF :REMSCHEID, GERMANY.

MANUFACTURE OF SEAM LESS Tunas.

srncrrrcarron forming part of Letters Patent No; 361,956, dated April 26; rear.

Application filed March 28, 1887. Serial No.232j9l. (ModcLl Patented in England January 27, 1885, No. 1,167; in France J anunary 27, 1885, No. 168,433; in Germany January 27, 1885. No. 34,617; in Belgium January 27, 1885, No. 67,667; in Italy January 26,1836, No. 7,925; in Lnxemburg June '20, 1886, No. 704 ;-in Spain August 21, 1886, No. 9,537, and in Austria-Hangar September 18, 1886.

- factoring Seamless Metallic Tubing, of which the following is a specification This invention is a modification-of the invention which I have shown and described in another pending application for a patent, re-

lating to the manufacture of seamless tubing from solid metallic blanks by the employment of diagonally-acting rolis, the working-faces of which converge, and between which there is placed a slender rod for holding back the solid central portion of the blank during its -endwise progress between the rolls and conse- 'quent transformation into a tube.

The present invention is especially applicable to the manufacture of seamless tubing from solid metallic blanks composed of metals or alloys which are so soft and ductile as not to I require to be heated to a high temperature to rfit'thexn for sulgction to the action of the rolls.

v The/invenlion-consists in the combination, with suitably-adjusted diagonally-acting rolls having'convergent working-faees, 'ot a cone- 'po'inted mandrel, which is arranged to project Y 'ja'prescribed distance into the space between 3o the working-faces of the rolls, and hence to penetratethe center of the forwardly-progressand to thereafter serve as an anvil over the surface of which the metal the blank is forced by the reducing i'ng blank orv former, composing I 5" and stretching action of the diagonally-acting convergent rolls, and is thustransfprmed into a tube, the interior diameter of jwhichds de- "termined-by-the.. diameter of thebase ofthe cone, and the exterior diameter of which is 0 determined by the width of the narrowest part pace betweenthe working-faces of the of the B. 7 rolls. The diagonally-acting rolls are feedinginasm'nch as they perform the function i .of feedingthe blank forward against and'ov'er 4 the' snrfaceof the conical or conoidnl mandrel,

' and it wiii be seen'that the apparatus maybe employed for reducing the thickness of the shell of a tube already; formed by enlarging its interior diameter.

As diagonal rollingmachines ,are well known, they need not be herein described in detail. The accompanying drawings there{ fore are simply-' designd to show a p'air-of diagonallyacting rolls, having convergent working-faces and arranged on either side of a con-pointed m'andrehthqshaft of whichis stepped or journaled in a standard orsome central longitudinal section a blank which has so farprogressed-jn its passage between the rolls that the tubular formation has been iniemt-ion of transforming a solid. blank into a tube, and Fig-"4" illustrates the conclusion of the operation. t i For the sake of clearness in'illustration and description, it is assumed that in the machine th'e'o'perative parts ofwhich are illustrated in the drawings two conical diagonal rollsare employed, and that the vertical planesof the axes of these rolls are parallel, but incline in opposite directiorfs from the horizontal plane of the mandrel, which is interposed between the rolls. It willbe understood, however, that three, or even four, rolls may be employed in connection with the mandrel. hen more thanatwo rolls are employed they serveto cen-' tralize the blank.' When only two .rolls are employed. the centralization of the blank is efiected by means of suitablegnides. As, however, the einployment ef ,guides in combina tion with two diagonal -rolls is well known, it

is deemed unnecessary to herein show or describe them in detail.

The operative parts illustrated in the drawmgs consist of the conical rolls A, a, which are gay res ectively'arranged on either sideof a'eonical mandrel, B, which rejects into the narrowerend-of the spacebe ween the working faces of r the rolls to such an eiitent as tocause its small end b to-penetrate into the central portion of the solid blank 0 after the blank has been engaged byitlierolls and hascom'menced tqnrove a 6 tiated at its forward end. Figs. 2 and-3illnstrate successive intermediate stagesin the opforward. The mandrel-shaft B is stepped or s journaled'in the standard D or in some other ing-faces of the rolls may be stationary part of the machine.

In some cases it may be desirable to permit the mandrel to be rotated by the friction upon its surface of the-rotating blank. In other cases it may be preferred to hold themandrel rigidly, so that it cannot revolve.

As the blank continues its progress between the working-faces of the rolls themetal is forced forward over the mandrel, as shown in Fig. 2, and acquires the form of the hollow cylinder 0, (shown in Fig. 3,) in which the rear end, 0, of the biank is represented as having been carried forwar nearly to the pointed end b of the mandrel.

Fig. 4 represents the conclusion of the tubeforming operation, after which the shaft may be disengaged from the socket d, in which it is stepped or journaled, and the finished tube then slipped ofl the shaft.

It will of course be understood that instead of the conical rolls shown in the drawings, rolls of other forms or kinds may be employed; and it will also be understood that the workmade to converge more or less abruptly, as may befound necessary in practice in operating upon different metals.

The workingaces of the rolls may also, if required, be provided with spiral ribs or corrugations, for the purpose of enabling cross-section,-

them to take a more effective hold. upon the metal at the surface of the blankagainst which they impinge.

"The mandrel may be of any suitable form in formof a movable or detachable head seated in the end of a long bar of smaller diameter than the inner diameter of the tubular product. The mandrel may also be made hollow,

and cooledrbymeans of an injectedicooling fluid; but for the'manufacture of tubes from soft metalsit is preferred to use solid mandrels,

bination, as herein' shown and is preferably made in the' "'smaller'ends.

twist' is imparted to the 'shell of the tubular formation while the shell isbeing progressively reduced in thickness by being compressed upon the surface of' the conical man- What is claimed as the invention is 1. The herein-described improvement in the art of' forming a solid metallic blank into a tube of prescribed diameter and thickness of shell, in which,- by the impingement upon the blank of diagonally-acting rolls having convergent working-faces, the blank is reduced in diameter and the metal thereof is forced against the small end and over the surface of a conical mandrel, which acts as an anvil or former, upon the surface or upon some part of the surface of which the shell of the tube in process of formation is compressed by therolls and its thickness thereby determined. 2. In diagonal-rolling machines, the combination, as herein set forth, of diagonally-acting feeding-rolls with a conical mandrel projecting a prescribed distance into the space between theworking-faces of the rolls and serving as an anvil or former, against and over thesurface of which the metal of the blank is forced by the action of the rolls. g

3. In diagonal-rolling machines, the comand described, of a conical mandrel with diagonally-acting conical rolls arranged on different sides of the path through which. the blank travels, with their larger ends nearer together than their REINHARD MANNESMANN.

Witnesses:

FRITZ KOEGEL, GUSTAVE ALBERT Ogznnrons. I 

